The present disclosure relates to variable cycle gas turbine engines, and more particularly to a span-adaptive stator therefore.
Gas turbine engines, such as those that power modern commercial and military aircraft, generally include a compressor section to pressurize an airflow, a combustor section to burn a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases.
Most turbofan engines split the airflow into two streams downstream of a fan. An inner stream enters the core, there to undergo further compression, mix with fuel, burn, and then generate mechanical shaft power by passage through a turbine. This core stream may then exit through a nozzle. The outer stream bypasses the core either to exit the engine through its own separate nozzle or is mixed into the core stream before exit through a common nozzle.
More recently, variable cycle gas turbine engines, or so called three-stream architectures have been proposed in which in addition to the inner core stream, the outer stream may be split into two or more additional streams in separate ducts. There may be additional turbomachinery stages deployed amongst the streams in various architectures. Typically, the outer stream is so split in order that the total temperature and total pressure of the two outer streams may differ according to mission needs.
These three-stream engine architectures can result in increased overall aircraft performance for some missions, especially those with widely varying requirements such as supercruise and loiter. In some applications, however, the penalties in complexity and weight associated with conventional three-stream architectures may negate the benefits.